Printing machine



March 6, 1934. Wv DEPENBROCK H,95@,373

PRINTING MACHINE Filed July 27. 1931 2 Sheets-Sheet 1 March 6, 1934 w. DEPENBROCK 1,950,373

PRINTING MACHINE Filed July 27. 1931 ZShets-Sheet 2 Fig-3 .such stops must be provided for.

@atentecl Mar. 6, 1934 UNITED STATES PATENT; orr cr.

PRINTING MACHINE Wilhelm Depenbrock, Kreuznach, Germany, as-

signor to Seitz-Werke Germany, a firm G. in. b. H., Kreuznach,

Application July 27, 1931, Serial No. 553,446 In Germany June 5, 1931 6 Claims.

Icorrect position for example within a predetermined printing space. If sheets of different sizes are to be printed in which the printing spaces have a variable distance from the edges of the sheet an appropriately large number of With such an arrangement material difficulties are encountered in endeavouring quickly to locate the requisite stops. In the case of twenty or more different sheet sizes it will generally be impossible to effect the manipulation without a particular index or key enabling the requisite stops to be readily selected. Even so, however, mistakes are still liable to occur and the insertion of the sheet becomes very laborious.

According to the invention the above drawbacks are avoided. The invention resides in that the printing space of the machine is rendered conspicuous by light enabling it and the preprinted impression space on the form or sheet ;to be readily brought into register. For this purpose it is quite immaterial where the impression space on the different sheets is actually located as in each instance the sheet can quickly and safely be brought into the correct position.

This marking out of the impression space for example can be effected by the bed plate beingprovided with an appropriate aperture facing the type and covered with a transparent printing support associated with a source of light working from below so as to throw light through the sheet. Where nontransparent cardboard sheets or the like are used the impression space is illuminated and defined preferably from above by a source of light which may be located laterally of the printing mechanism.

The accompanying drawings illustrate two constructional examples of the invention.

Figs. 1 and 2 represent one form of the invention respectively in transverse section and top plan view and Fig. 3 illustrates a second construction in perspective view.

According to Figs. 1 and 2 the printing bed or plate a serving as a support for the sheet during printing has at the place facing the printing .ithe plate a is a source of light d for example a glow lamp which throws its light through the transparent support 0 across the opening b. In order more sharply to confine the contours of the impression space thus marked, use may be made if need be, as shown in the drawing, of a special screen or frame of thin sheet metal which is provided with a cut-out g corresponding precisely to the impression space. Upon placing on the bed plate a a sheet of paper which is not too thick while the light is thrown through the aperture b the rays of light from the lamp (1 will penetrate also the sheet over a space sharply defined by the aperture b and the screen 9. Consequently it is possible without difliculty so to displace the sheet as to bring any predetermined IQ impression space thereon into precise register with the space illuminated over the aperture 9.

Where relatively thick paper sheets are used, such as for example, cardboard, the light from a glow lamp 11 would not generally be able to penetrate the sheet. In this case the marking out of the impression space h (Fig. 3) is preferably effected by a source of light illuminating the sheet or plate a from above. In this way the impression space can likewise be precisely defined, enabling the sheet therefore as in the previous example to be readily brought into the precise position without the use of special registering stops or lays. The source of light may if desired be embodied in the printing mechanism i close to the type set up for printing.

I claim:

1. In a printing machine, the combination with a source of light, a bed plate having portions corresponding to the effective printing area of the machine illuminated by the source of light, the said bed plate having an aperture coinciding with the impression space receiving the aforesaid illumination, and a light permeable support fitted in the aperture.

2. In a printing machine, the combination with a source of light, a bed plate, portions of which are illuminated by said light and effective to designate locations of the limits of the operative printing area of the printing form.

3. In a printing machine, the combination of a source of light and a bed plate, the said bed plate having an aperture indicating the space where the printing occurs illumined by the source of light, such illumined area being visible through a paper sheet deposited on the bed plate to be printed whereby the printing space of the paper sheet can be positioned with respect to the cone of light.

4. A printing machine according to claim 3 in will likewise be illuminated whereby the said sheet may be properly positioned with relation to the efiective area of the printing machine.

6. In a printing machine, the combination of a bed plate and a source of light arranged above said bed plate, said source of light designating by light rays the limits of the effective printing area itself on said bed plate and on a sheet of paper positioned thereon.

WILH. DEPENBROCK. 

